Clinching punch



July 19, 1966 K. J. KLENK 3,261,073

CLINCHING PUNCH Filed June 2, 1965 INVENTOR.

BY "'5 8 M25.

' ATTR/VEY United States Patent 3,261,073 CLINCHING PUNCH Karl J. Klenk, Chadds Ford, Pa. (20 Germay Industrial Park, Wilmington, Del.) Filed June 2, 1965, Ser. No. 460,767 4 Claims. (Cl. 29-21.1)

The invention herein disclosed relates to tools of the hand punch type and the special objects of the invention are to provide a practical and efficient hand tool which will perforate layers of sheet material and as a part of the punching operation, clinch the layers solidly together.

Particularly it is a purpose of the invention to provide such a tool which will have the added power necessary to effectively clinch the materials together.

These and other desirable objects have been attained by a novel combination of toggle links actuated by bell cranks on hand levers for advancing a punch plunger and cams acting on the bell cranks to effect a final powerful material clinching movement of the punch plunger.

Other novel features of the invention and further desirable objects accomplished are set forth and will appear in the course of the following specification.

The drawing accompanying and forming part of the specification illustrates a present preferred embodiment of the invention, but structure may be modified and changed as regards this illustration; all within the true intent and scope of the invention as hereinafter defined and claimed.

FIG. 1 in the drawing is a front elevation of the tool in the open or retracted position; parts broken away and appearing in section.

FIG. 2 is a similar view showing the parts in the projected clinching position.

FIG. 3 is a broken sectional detail illustrating the material clinching action.

The head or base portion of the tool is shown as of a C-shaped formation embodying vertically spaced upper and lower generally parallel arms 1, 2, connected in that spaced relation by a back portion 3.

The punch elements are shown as a die member 4, set in the upper arm of the head and a companion punch member 5, carried by a plunger 6, operating up through the lower arm of the head.

The hand grip levers 7 and 8, are shown pivoted at 9 and 10 to the lower arm of the head at opposite sides of the plunger.

Bell crank levers 11, 12 are pivoted at their elbows on the hand levers at 13, 14, with lower, shorter lever arms 15, 16, extending inwardly toward the plunger and upper, longer lever arms 17, 18 extending upwardly and carrying cam rolls 19, 20, in riding engagement with earns 21, 22, dependent from the head.

These cams are of rigid construction and have downwardly divergent cam faces designed in the closing movement of the hand levers to spread th bell cranks and impart a final lifting movement to the plunger and hence to the clinching punch.

This is effected by the toggle links 23, 24, pivoted at their outer ends at 25, 26, to the shorter arms of the bell cranks and pivoted at their meeting inner ends at 27, to the bracket 28 on the lower end of the plunger.

A coiled spring 29, surrounding the plunger and interposed between the head and the bracket 28, serves to spread the handles, retract the plunger and hold the bell cranks rocked toward each other, with rolls in engagement with the cam surfaces.

3,261,073 Patented July 19, 1966 The punch is shown as a shearing punch having flat angled terminal faces 30, tapered to a sharp point and providing sharp cutting edges at the junctures of such faces so as to cut the material into separate flaps or tabs as shown at 31, in FIG. 3, and which tabs will be spread into riveting formation as the punch completes its movement through the layers of material 32, 33.

The cams at opposite sides of the plunger divide the work and so can be designed to give all pressure necessary without requiring too great hand pressure on the levers.

The shape of the cam faces may be varied to suit different kinds of work, that shown being generally satisfactory for work such as clinching layers of sheet metal together. A latch for securing the tool in closed position is shown at 34, FIG. 1, engaged on the toggle pivot 25 and arranged to hook over the pivot pin 14 on the opposite handle member 8.

What is claimed is: 1. A punching and clinching tool comprising a C-shaped punch head having vertically spaced upper and lower generally parallel arms and laterally spaced rigid cams dependent from said lower arm,

companion punch and die elements on said upper and lower arms and including a punch plunger extending between said cams up through said lower arm and a cooperating punch element on said upper arm,

hand levers pivoted at their upper ends to the lower arm of the punch head at opposite sides of said plunger,

bell cranks pivoted at their elbows on said hand levers and having short lever arms extending toward said plunger and longer lever arms projecting upward toward said cams,

rollers on the upper ends of said longer lever arms in riding engagement with said cams and toggle links pivotally connected between said short arms and said plunger. 2. A punching and clinching tool comprising a C-shaped punch head having vertically spaced upper and lower generally parallel arms and laterally spaced rigid cams dependent from said lower arm,

companion punch and die elements on said upper and lower arms and including a punch plunger extending between said cams up through said lower arm and a cooperating punch element on said upper arm,

hand levers pivoted at their upper ends to the lower arm of the punch head at opposite sides of said plunger,

bell cranks pivoted at their elbows on said hand levers and having short lever arms extending toward said plunger and longer lever arms projecting upward toward said cams,

rollers on the upper ends of said longer lever arms in riding engagement with said cams and toggle links pivotally connected between said short arms and said plunger,

said cams having cam surfaces inclined downwardly away from said plunger and a spring on said plunger for depressing the same and holding said bell cranks with the rollers engaged with said cams.

3. The invention according to claim 1 in which said companion punch and die elements comprise a pointed piercing punch on said plunger having inclined shearing edges and a die to receive said punch and portions of material sheared by the same.

4. The invention according to claim 1 with a latch for securing the tool in closed position and comprising a hook 3 4 member pivoted to send toggle links and arranged to make FOREIGN PATENTS hooked engagement with one of said hand levers. 274,720 7 1927 Great Britain References Cited by the Examiner 745380 2/1956 Great Bntam' UNITED STATES PATENTS 5 WILLIAM FELDMAN, Primary Examiner. 351,645 10/ 1886 McGill 30 6 G. WEIDENFELD, Assistant Examiner. 2,333,966 11/1943 Weiss 29-211 

1. A PUNCHING AND CLINCHING TOOL COMPRISING A C-SHAPED PUNCH HEAD HAVING VERTICALLY SPACED UPPER AND LOWER GENERALLY PARALLEL ARMS AND LATERALLY SPACED RIGID CAMS DEPENDENT FROM SAID LOWER ARM, COMPANION PUNCH AND DIE ELEMENTS ON SAID UPPER AND LOWER ARMS AND INCLUDING A PUNCH PLUNGER EXTENDING BETWEEN SAID CAMS UP THROUGH SAID LOWER ARM AND A COOPERATING PUNCH ELEMENT ON SAID UPPER ARM, HAND LEVERS PIVOTED AT THEIR UPPER ENDS TO THE LOWER ARM OF THE PUNCH HEAD AT OPPOSITE SIDES OF SAID PLUNGER, BELL CRANKS PIVOTED AT THEIR ELBOWS ON SAID HAND LEVERS AND HAVING SHORT LEVER ARMS EXTENDING TOWARD SAID PLUNGER AND LONGER LEVER ARMS PROJECTING UPWARD TOWARD SAID CAMS, ROLLERS ON THE UPPER ENDS OF SAID LONGER LEVER ARMS IN RIDING ENGAGEMENT WITH SAID CAMS AND 